Regulator for fuel burners



Feb. 14, 1939. J. w. HARRIE REGULATOR FOR FUEL BURNERS Filed Sept. 11, l93 2 Sheets-Sheet 1 INVENTOR.

JAMES W HARRIE 9% W ATTORNEY.

Feb. 14, 1939. J. w. HARRIE REGULATOR FOR FUEL BURNERS Filed Sept. 11, 1936 Z Sheets-Sheet 2 INVENTOR JAMES W. HARRIE BY ATTORNEY Patented Feb. 14, 1939 UNITED STATES PATENT OFFICE 2,147,294 REGULATOR FOR FUEL BURNERS Application September 11, 1936, Serial No. 100,311

Claims.

This invention relates to control apparatus, and particularly to apparatus adapted to be employed to control the supply of fuel and air to the burner of a furnace in response. to variatons in the pres- 5 sure of the steam in the boiler heated by the furnace.

It is an object of this invention to provide control apparatus of the type described and which operates to gradually vary the rate of supply of fuel to the furnace throughout the entire range of movement of the control apparatus, instead of varying it by fixed steps.

A further object of the invention is to provide control apparatus of this type and employing a control unit which can be assembled and adjusted at the factory, and shipped to the place of installation as a complete unit.

Another object of the invention is to provide a control unit responsive to fluid pressures, and incorporating adjusting means to vary the pressure to which it responds, and having other adjusting means to vary the range of movement of a position of the control unit in response to a given change in the pressure of the fluid to which the unit is subject.

A further object of the invention is to provide an improved control apparatus.

Other objects of the invention and features of novelty will be apparent from the following description taken in connection with the accompanying drawings, in which Fig. 1 is a view of a furnace equipped with control apparatus embodying my invention,

Fig. 2 is an enlarged sectional view of the control device employed in the control apparatus shown in Fig. 1,

Fig. 3 is an enlarged sectional view of a modifl d form of control device provided by my invention,

Fig. 4 is a sectional view taken substantially along the line 44 of Fig. 3, and

Fig. 5 is a sectional view taken substantially along the line 55 of Fig. 3.

In Fig. 1 of the drawings there is illustrated a furnace l which may be of any Well known construction. The furnace I has a burner which is supplied with suitable fuel, such as oil or gas, through a pipe 2, while a valve device 4 is interposed in this pipe to regulate the rate of supply of fuel to the burner. The supply of air to the furnace fire box is controlled by means of a draft door 5, and the rate of flow of burned gas from the furnace fire box through the smoke pipe 6 is controlled by means of a damper 8. p

The setting of the valve device 4, the draft door 5, and the damper 8 are. controlled in response to variations in the pressure of the steam in a boiler, not shown, heated by the furnace l by means of a control device provided by this invention and indicated generally by the reference numeral It The construction of the control device I0 is shown in Fig. 2 of the drawings, and, as illustrated, comprises a movable abutment in the form of a diaphragm l2, which is clamped between confronting flanges on a cover I4 and a body IS. The diaphragm I2 is subject to the opposing forces of the .fluid in a chamber l8, which is connected by way of a pipe 20 with the boiler of the furnace l, and of a spring 22, which extends between a plate. 24 which engages a face of the diaphragm l2, and a spring seat 26, which is supported on a bushing 28 which is adjustably secured on the body I6.

A stem 30 has one end thereof secured to the diaphragm l2, and its other end engagesa face of a lever 32, which is pivotally supported adjacent one endon the body l6.

The other face of the lever 32 engages the end of a stem 34 of a pilot valve device 36 for controlling the supply of fluid under-pressure to and the release of fluid under pressure from a chamber 38 at the face of a movable abutment in the form of a piston 40, which is mounted in a bore in a cylinder 42. The piston 40 has secured thereto a piston rod 44, which extends through the end wall of the chamber 38, the opening through which it extends being sealed by means of packing 46, which is held in place by means of a packing nut 48.

p The pilotvalve device 36 comprises a ball valve 50 mounted in a chamber 52, which is constantly connected by way of a passage and pipe 54 with a suitable source of fluid under pressure, such as a municipal water supply system. The. ball valve 50 is urged by aspring 56 into engagement with aseat separating the chamber 52 and a chamber 58, which is constantly connected by way of a passage 60 with the chamber 38 at the face of the piston 40.

The stem 34 of the pilot valve device 36 extends through a chamber 62, which is constantly connected by way of a passage and pipe 64 with a suitable drain, and this pipe is also connected to the chamber .66 at the upper face of the piston 40. The flow of fluid from the chamber 62 to the atmosphere around the stem 34 is prevented by packing v68, which is held in place by means of a packing nut 10 and a gland l2. Unintended flow of fluid between the chamber 58 and the chamber 62 is prevented by packing 14, which is held in place by means of a gland 16, while a spring I8 extends between the gland I6 and a spring seat 80 secured on the stem 34, and yieldingly urges the stem upward, as viewed in Fig. 2 of the drawings.

The lower end of the stem 34 has a seat formed thereon which is adapted to engage the surface of the ball valve 50, while the stem 34 has a passage 82 formed therein which communicates with the area on the end of the stem within the seat thereon, and with the chamber 62.

The control device provided by this invention has means responsive to movement of the piston 40 for varying the force exerted on the lever 32, and thereby on the diaphragm I2. As shown this means comprises a spring 90 which extends between a spring seat 92, which is engaged by an adjusting screw 64 carried by the lever 32, and a spring seat 66, which engages an arm 98 of a bell crank I00, which is rotatably supported upon a pin I02. 7

The other arm I04 of the bell crank I has a roller I66 pivotally supported thereon, while the body of the control device has a guide roller I08 rotatably supported thereon adjacent the roller 506. A wedge IIO carried by an arm II6, which is secured to the piston rod 44 extends between the rollers I06 and I08 and has surfaces indicated at H8 and I20 thereon which are engaged by the rollers I08 and I06, respectively. The surface II8 is substantially parallel to the plane in which the piston 40 moves, while the. surface I20 extends at an angle to the surface II8, substantially as shown in Fig. 2 of the drawings.

The piston rod 44 has a yoke I22 secured to the lower end thereof, and this yoke is connected by means of a chain I24 with a lever I26, which is pivotally supported intermediate its ends by a pin I21 on a bracket I28 carried by the furnace I. The lever I26 has a weight I30 secured on the end thereof which yieldingly urges the lever in a clockwise direction, as viewed in Fig. 1 of the drawings.

The fuel supply valve device 4 is pivotally connected to the lever I26 by means of a link I32, which is connected to the lever I26 at a point on the side of the pin I21 adjacent the point of connection of the chain I24 therewith. The fuel supply valve device 4 is arranged to decrease the rate of supply of fuel to the furnace on upward movement of the link I32, and to increase the rate of supply of fuel to the furnace on downward movement of the link I32.

The draft door has an arm I34 associated therewith and this arm is connected to the lever I26 by means of a chain I36, while the damper 8 has a lever I38 associated therewith and this lever is connected to the lever I26 by means of a chain I40. The lever I38 has a weight I42 secured thereon which yieldingly urges the lever I38 in a counterclockwise direction, as viewed in Fig. l of the drawings, so as to move the damper 8 to its full open position.

The control apparatus is shown in Figs. 1 and 2 of the drawings in the position which it assumes when the pressure of the steam in the boiler of the furnace I is substantially at the pressure which the control apparatus is intended to maintain, and with the control apparatus in a position to partially open the draft door 5 and the damper 8, and to condition the valve device 4 to supply fuel to the furnace burner at the rate intermediate the maximum and minimum rates.

On an increase in the pressure of the steam in the boiler of the furnace I there will be a similar increase in the pressure of the fluid in the chamber I8, and a corresponding increase in the force exerted on the diaphragm I 2 in opposition to the force exerted thereon by the spring 22 and by the spring 90 acting through the lever 32 and the stem 30. As a result of this increase in the pressure of the fluid in the chamber I8, the diaphragm I2 will be forced downwardly, thereby compressing the spring 22 somewhat, and this movement of the diaphragm will be transmitted through the stem 30 to move the free end of the lever 32 downwardly, and on this movement of the lever 32 it presses against the end of the stem 34 of the pilot valve device 26 and moves it downwardly, while the spring 90 is compressed.

On downward movement of the stem 34, the end thereof presses against the ball valve 50 and moves this valve away from its seat against the spring 56 so that fluid under pressure supplied by way of the pipe and passage 54 to the chamber 52 flows therefrom to the chamber 58, and thence by way of the passage 60 to the chamber 38 at the face of the piston 40.

On the supply of fluid under pressure to the chamber 38, the piston 40 is moved upwardly in the cylinder 42, thereby moving the piston rod 44 and the yoke I22 upwardly.

On upward movement of the yoke I22, force is exerted through the chain I24 to move the lever I26 in a counterclockwise direction about the pin I21 and on this movement of the lever I26, force is exerted through the link I32 to condition the valve device 4 to reduce the rate of supply of fuel to the burner of the furnace.

In addition, on this movement of the lever I26, the left hand end of the lever is moved downwardly so as to permit the draft door 5 to be moved by gravity towards its closed position, while force is exerted through the chain I40 on the lever I38 so as to move the damper 8 towards its closed position in the smoke pipe 6. It will be seen, therefore, that on the supply of fluid under pressure to the chamber 38 at the face of the piston 40, there is a reduction in the rate of supply of fuel to the burner of the furnace I, and that the draft door 5 and the damper 8 are moved towards their closed positions.

On upward movement of the piston 40, the arm H6 is moved upwardly so that the wedge H0 is moved between the rollers I06 and I08. On this movement of the wedge IIO, the surface II8 thereon moves across the guide roller I08, while the inclined surface I 20 on the wedge I I 0 engages the roller I06 and gradually moves it to the left, as viewed in Fig. 2 of the drawings.

On this movement of the roller I06, the bell crank I00 is moved in a clockwise direction about the pin I02 so as to move the arm 98 upwardly to compress the spring 90.

On this upward movement of the arm 98 of the bell crank I00 there is an increase in the force exerted through the spring 90 on the free end of the lever 32 and tending to move it upwardly against the opposing force of the fluid under pressure in the chamber I8 at the face of the diaphragm I2.

As a result of this increase in the force exerted on the diaphragm I2, the diaphragm will be moved upwardly a short distance, while the free end of the lever 32 will be moved upwardly. On this upward movement of the free end of the lever 32, the end of the stem 34 of the pilot valve device 36 is held in engagement therewith by the spring 56 acting through the ball valve 50 and by the spring 18, while the ball valve 50 is moved towards its seat so as to reduce the rate of flow of fluid from the chamber 52 to the chamber 58, and thus to the chamber 38 at the face of the piston 48.

When the piston 48 has moved upwardly in the cylinder 42 a predetermined distance, the wedge I I8 will have been moved far enough between the rollers I 86 and I88 to move the bell crank I88 so as to compress the spring 98 sufiiciently to increase the force exerted on the lever 32, and through this lever and the stem 38 on the diaphragm I2, by an amount equal to the increase in the force exerted on this diaphragm as a result of the increase in the pressure of the steam in the boiler heated by the furnace I.

When the spring 98 has been compressed to this degree, the lever 32 will be moved to a position to move the diaphragm I2 to its normal position, while the lever 32 is moved to a position to permit the spring 56 to move the ball valve 58 to the seated position to cut off the supply of fluid to the chamber 38 and thus cut off upward movement of the piston 48. The lever 32 will be held in a position such, however, that the end of the stem 34 will be held in engagement with the face of the ball valve 58 so as to prevent the flow of fluid from the chamber 58 to the passage 82 in the stem 34, and thence to the drain by way of the passage and pipe 64. This prevents the release of fluid from the chamber 38 at the face of the piston 48 so that the piston 48 will be maintained in the position to which it has been moved.

On a subsequent reduction in the pressure of the steam in the boiler of the furnace I there is a similar reduction in the pressure of the fluid in the chamber I8 at the face of the diaphragm I2 and a corresponding reduction in the force exerted by this fluid on the diaphragm I2 and opposing the force exerted thereon by the spring 22, and by the spring 98 acting through the lever 32 and the stem 38. On this reduction in the pressure of the fluid in the chamber I8, the springs 22 and 88 expand slightly and move the central portion of the diaphragm I2 and the stem 38 upwardly so that the free end of the lever 32 is moved upwardly, as viewed in Fig. 2 of the drawings, by the spring 98, and on this movement of the lever 32, the stem 34 of the pilot valve device 36 is moved upwardly by the spring I8.

On upward movement of the stem 34 by the spring I8, the end of the stem 34 is moved away from the ball valve 58, which is held in the seated position by the spring 56.

On movement of the end of the stem 34 away from the ball valve 58, fluid is permitted to flow from the chamber 38 at the face of the piston 48 through the passage 68 to the chamber 58, and thence through the passage 82 in the stem 34 to the chamber 62 from which it flows to the drain by way of the passage and pipe 64.

On the release of fluid from the chamber 38 at the face of the piston 48, the piston, the piston rod 44, and the yoke I22 are moved downwardly, as viewed in Figs. 1 and 2 of the drawings, by the weight I42 on the lever I38 and the weight I38 on the lever I26.

On this movement of the piston 48, the lever I26 is moved in a clockwise direction about the pin I21 and its movement is transmitted through the link I32 to the valve device 4 to condition the valve device to increase the rate of supply of fuel to the burner of the furnace I.

In addition, on this movement of the lever I26 force is exerted through the chain I36 on the arm I34 associated with the draft door 5 to move this draft door towards its full open position. Also on this movement of the lever I26, the weight I42 is permitted to turn the lever I38 so as to move the damper 8 towards its full open position in the smoke pipe 6.

On this movement of the piston 48 and the piston rod 44, the arm II6carried by the piston rod 44 is moved downwardly, while the wedge I I8 is moved downwardly between the rollers I86 and I88.

On this movement of the wedge III], the surface II8 thereon moves across the guide roller I88, while the surface I28 is moved across the roller I86, which is held in engagement with the inclined surface I28 by the spring 88, which expands and turns the bell crank I88 on the pin I82. On the expansion of the spring 98 there is a reduction in the force exerted by this spring on the end of the lever 32 and tending to hold the lever 32 and the diaphragm I2 against the opposing force of the fluid in the chamber I8.

As a result of this decrease in the force exerted on the diaphragm I2, the diaphragm will be moved downwardly a short distance by the fluid under pressure in the chamber I8, while the free end of the lever 32 will be moved downwardly. On this downward movement of the free end of the lever 32, the end of the stem 38 is moved downwardly against the opposing force of the spring I8 so that the seat on the end of the stem 34 is gradually moved adjacent the ball valve 58 so as to restrict the rate of flow of fluid from the chamber 38 to the chamber 58, and thence to the passage 82 in the stem 34, from which it flows to the chamber 62 and thence to the drain by way of the passage and pipe 68.

When the piston 48 has been moved downwardly in the cylinder 42 a predetermined distance, the wedge I I8 will have been moved far enough to permit the bell crank I88 to be moved in a counterclockwise direction about the pin I82 so as to permit the spring 98 to expand sufficiently to decrease the force exerted on the lever 32, and through this lever and the stem 38 on the diaphragm I2 by .an amount equal to the ball valve 58 so .as to cut oil the release of fluid from the chamber 38 on the face of the piston 48 through the passage 82 in the stem 34.

When the release of fluid from the chamber 38 is out off further downward movement of the piston 48 is prevented, and the piston 48 ismaintained in the position to which it has been moved, while the valve device 4, the draft door 5 and the damper 8 are held in the positions to which they have been moved.

On each subsequent change in the pressure of the steam in the boiler of the furnace I, the control device I8 operate-s as described in detail above to vary the settings of the valve device 4, and of the draft door 5 and damper 8.

It will be seen that the change in the rate of supply of fuel to the burner of the furnace in response to a change in the pressure of the steam in the furnace boiler is controlled in accordance with the change in the pressure of the steam in the boiler of the furnace as thepiston 48 is moved,

until the force exerted by the spring 90 on the diaphragm I2 has been varied an amount sulficient to offset the change in force exerted on this diaphragm by the pressure of the steam in the furnace boiler.

It will be seen also that the rate of supply of fuel to the furnace may be gradually varied throughout the entire range of movement of the control apparatus instead of being varied by fixed steps.

In addition, it will be seen that whenever the diaphragm I2 is moved away from its normal position in either direction as a result of a change in the pressure of the steam in the boiler, the control device operates to vary the force exerted on the diaphragm by the spring 90 so that the diaphragm will be promptly returned to its normal position.

In Figs. 3, 4 and 5 of the drawings there is illustrated a modified form of control device embodying my invention. This control device is similar in construction and operation to the control device shown in Figs. 1 and 2 of the drawings, and, as illustrated, comprises a diaphragm I50 which is clamped between confronting flanges on a cover I5I and a body I52, which is supported on a bracket I53.

The diaphragm I50 is subject on one face to the pressure of the fluid in a chamber I54, which is connected by way of a pipe I56 to the boiler of the furnace to be controlled, and is subject on the other face to the pressure of a spring I58, which extends between a plate I60 and a spring seat I62, which is adjustably supported from the body I52 on a threaded bushing I64.

The plate I60 is secured on the face of the diaphragm I50 by means of a threaded member I66 having a conical recess in the head thereof which is adapted to receive the rounded end portion of a stem I68. This end of the stem I68 has a hole therein through which extends a pin I10, while the stem I68 loosely extends through an opening in a hollow member I12, which is secured on the member I66 and secures the stem I68 to the diaphragm I50.

The stem I 68 extends through a bore in the bushing I64 and has a recess in the lower end thereof which is engaged by the end of a screw I12, which is adjustably secured in an opening in the lever I14 and is held in the adjusted position by means of a lock nut I15. The lever I14 has spaced recesses formed in the lower face thereof adjacent one end thereof, and these recesses are adapted to receive balls I16, which are mounted in similar recesses in the face of the bracket I53, as is best shown in Fig. 4 of the drawings, so as to pivotally support the lever I14 on the bracket I53.

The lever I14 also has adjustably secured in threaded openings therein, screws I18 and I which are held in their adjusted positions by means of lock nuts I8I and I82, respectively.

The end of the screw I18 extends into a recess in the end of a rod I 84, the other end of which has a recess formed therein which is adapted to receive the end of a stem I86 of a pilot valve device I88, which controls the supply and release of fluid under pressure to and from a chamber I90 at the face of a piston I92, which is mounted in the bore in a cylinder I94 carried by the bracket I53.

The piston I92 has secured thereto a piston rod I96, which extends through the end wall of the chamber I90, the opening through which it extends being sealed by means of packing I91 which is held in place by a gland I 98 and a packing nut I99. A sleeve I95 is loosely mounted on the piston rod. I96 and limits movement of the piston I92 towards the lower end of the bore in which it is mounted.

The pilot valve device I88 comprises a ball valve 200, which is mounted in a chamber 20I, which is constantly connected by way of a passage and pipe 202 to a suitable source of fluid under pressure, such as the municipal water supply system. The ball valve 200 is yieldingly urged by means of a spring 204 into engagement with a seat separating the chamber 20I from a chamber 206, which is connected by way of a passage 208 with the chamber I90 at the face of the piston I92.

The stem I86 extends into the chamber 206 and also extends through a chamber 2I0, which is constantly connected by way of a passage and pipe 2I2 with a suitable drain. The pipe 2I2 also communicates with the chamber 2I4 at the upper face of the piston I92.

The flow of fluid from the chamber 2I0 to the atmosphere around the stem I86 is prevented by packing 2I5, which is compressed between a gland 2I6 and a packing nut 2I8. Unintended flow of fluid between the chamber 206 and the chamber 2I0 around the stem I86 is prevented by means of packing 2I9, which is held in place by a gland 220, while a spring 222 extends between the gland 220 and a spring seat 224 secured on the stem I86, and yieldingly urges the stern upwardly, as viewed in the drawings.

The stem I86 has a passage 226 formed therein and communicating with the chamber 2I0, and with a port in the end of the stem I86 which is surrounded by a seat which is adapted to engage the face of the ball valve 200.

The end of the screw I80 carried by the lever I14 extends into a recess in the end of a spring cage 230 containing a spring 232, which extends between the spring cage 230 and a spring seat 234. The spring seat 234 has a stem which extends into a recess in the face of an arm 236 of a lever 238, which is pivotally supported by a pin 242 between the arms 240 of the bracket I53.

The lever 238 has another arm 244 thereon which has a forked end on which is rotatably supported a grooved roller 246, while one arm 240 of the bracket I53 has rotatably supported thereon adjacent the roller 246 as is best shown in Fig. 5 of the drawings, a similar grooved guide roller 248.

This control device, like that shown in Figs. 1 and 2 of the drawings, includes means to vary the force exerted by the spring 232 on the lever I 14, and thereby on the diaphragm I50, in response to movements of the piston I92. This means comprises an arm 250 which is rigidly secured to the piston rod I96, and which has rigidly secured thereto a rod 252, which extends substantially parallel to the piston rod I96.

The rod 252 engages the face of the guide roller 248, as is best shown in Figs. 3 and 5 of the drawings, and has secured at the upper end thereof a coupling 254 to which is pivotally secured a coupling 256. The rod 252, in addition, has secured thereto at a point intermediate its ends, a member 258 having a forked end, which is adapted to receive an end of a rod 260 secured to the coupling 256.

The member 258 has an adjusting screw 262 associated therewith which is held in the adjusted position by means of a lock nut 263. The adjusting screw 262 engages the end of the rod 260 so as to position the lower end of this rod relative to the rod 252. The rod 268 is engaged by the roller 246 carried by the arm 244 of the lever vice is intended to maintain, and with the piston I92 of the control device substantially intermediate the ends of its range of movement in the bore in the cylinder I94.

On an increase in the pressure of the steam in the boiler of the furnace controlled by this control device, there is a similar increase in the pressure of the fluid. in the chamber I54 at the face of the diaphragm I58, and a corresponding increase in the force exerted by this fluid on the diaphragm I58 against the opposing force of the spring I58, and of the spring 232 acting through the lever I14 and the stem I68.

On this increase in the force exerted on the diaphragm I59, the diaphragm is moved downwardly and its movement is transmitted through the stem I68 to the lever I14, causing the left hand end of this lever, as viewed in Fig. 3 of the drawings, to be moved downwardly so as to further compress the spring 232.

On this downward movement of the lever I14, the rod I84 is moved downwardly, and its movement is transmitted to the stem I86 of the pilot valve device I88. The stem I86 is moved downwardly and the end of the stem presses upon the ball valve 288 and moves it against the spring 284 away from its seat so as to permit fluid under pressure supplied by way of the pipe and passage 282 to the chamber 28I to flow therefrom to the chamber 286, and thence by way of the l; passage 288 to the chamber I98 at the face of the piston i92. On the supply of fluid under pressure to the chamber I98, the piston I92 is moved upwardly in the bore in the cylinder I94, and its movement is transmitted through the piston rod I96 to the yoke 218, to which is connected the apparatus to be controlled, such as the valve device for controlling the supply of fuel to the furnace, and the draft and damper.

On upward movement of the piston rod I96 there is a corresponding upward movement of the arm 258,. and the rod 252 is moved upwardly so as to move the rod 268 upwardly across the face of the grooved roller 246, while the rod 252 is guided by the roller 248.

As the lower end of the rod 268 is farther removed from the rod 252 than the upper end, on upward movement of the rod 252, the rod 268 presses against the roller 246 so as to move the lever 238 in a counterclockwise direction about the pin 242, thereby moving the arm 236 of the lever 288 upwardly-to press the spring seat 234 against the spring 232 and increase the degree of compression of this spring, thus increasing the force exerted by this spring on the end of the arm I14 and through this arm and the stem I68 upon the diaphragm I58.

As the free end of the arm I14 is moved upwardly as a result of the increase in the force exerted by the spring 232 thereon, the spring 222 of the pilot valve device I88 moves the stem I86 upwardly so as to permit the ball valve 288 to be moved towards its seat by the spring 284, thereby reducing the rate of flow of fluid to the chamber I98 at the face of the piston I92.

When the piston I 92 has been moved upwardly a predetermined distance, the rod 268 will have been moved upwardly far enough to move the lever 238 so as to increase the compression of the spring 232 sufliciently to increase the force exerted thereby on the lever I14, and through the stem I68 on the diaphragm I58, so as to substantially offset the increase in force exerted on the diaphragm I58 as a result of the increase in the pressure of the steam in the boiler of the furnace controlled by the control device.

When the spring 232 has been compressed to this extent, the lever I14 will have been moved upwardly far enough to cause the diaphragm I 58 to be returned substantially to its normalposition, while the lever I14 is in such a position as to permit the ball valve 288 to be moved to its seated position by the spring 284, and at the same time to hold the end of the stem I 86 in engagement with the ball valve 288.

On movement of the ball valve 288 to the seated position, the supply of fluid under pressure to the chamber I98 at the face of the piston I92 is out off, and as the stem I86 is held in engagement with the ball valve 288, the release of fluid under pressure from the chamber I98 through the passage 226 in the stem I86 is prevented. The piston I82, therefore, will be held in the position to which it has been moved, while further upward movement of the piston will be cut off.

On a decrease in the pressure of the fluid in the boiler of the furnace controlled by the control device, there is a. similar decrease in the pressure of the fluid in the chamber I54 at the face of the diaphragm I58, and a corresponding reduction in the force exerted by this fluid on the diaphragm I58 in opposition to the force exerted thereon by the spring I58, and by the spring 232 acting through the lever I14 and the stem I68.

On this reduction in the pressure of the fluid in the chamber I54, the central portion of the diaphragm I58 will be moved upwardly by the spring I58, assisted by the spring 282, while the left hand end of the lever I14 will be moved upwardly a short distance by the spring 232 which expands somewhat.

On this upward movement of the lever M8, the stem I86 of the pilot valve device I68 is moved upwardly by the spring 222 so that the end of the stem is moved away from the ball valve 288, which is held in seated position by the spring 268.

On movement of the stem I86 away from the ball valve 288, fluid under pressure may flow to the passage 226 in the stem I86 from the chamber I98 at the face of the piston I92, and thence to the chamber 2I8,'from which it flows to the drain by way of the passage and pipe 2I2.

On the release of fluid from the chamber I98, the piston I92 and the piston rod 596 are moved downwardly by the biasing means associated with the apparatus controlled by the control device, and on this downwardmovement of the piston rod I86, the arm 258 is moved downwardly, thereby moving the rod 252 and the rod 269 downwardly.

On downward movement of the rod 268, as the upper portion of the rod is less distant from the rod 252 than the lower portion thereof, the lever 238 will be moved in a clockwise direction, as viewed in Fig. 3 of the drawings, so as to maintain the lever 246 in engagement with the rod 260.

On this movement of the lever 238, the arm 236 thereof is moved downwardly, as viewed in Fig. 3 of the drawings, thereby permitting the spring 232 to expand somewhat, thus reducing the force exerted by this spring on the lever I14 and through the stem I68 on the diaphragm I50.

On this reduction in the force exerted on the diaphragm I in opposition to the force exerted thereon by the fluid under pressure in the chamber I54, the diaphragm I50 is moved downwardly and its movement is transmitted through the stem I68 to the lever I14, to move it downwardly. On this movement of the lever I14, the rod I84 is pressed against the end of the stem I86 to move the stem downwardly against the opposing force of the spring 222, while the end of the stem I86 is moved adjacent the ball valve 200 so as to reduce the rate of release of fluid from the chamber I90.

When the piston I92 has been moved downwardly a predetermined distance, the rod 260 will have been moved downwardly far enough to permit the lever 238 to be moved, so as to decrease the compression of the spring 232 sufiiciently to decrease the force exerted on the lever I14, and through the stem I68 on the diaphragm I50, so as to substantially offset the decrease in force exerted on the diaphragm I50 as a result of the decrease in the pressure of the steam in the boiler of the furnace controlled by the device.

When the spring 232 has been expanded to this extent, the lever I14 will have been moved downwardly far enough to permit the diaphragm I50 to be returned substantially to its normal position, While the lever I14 is moved to a position to press the end of the stem I86 against the ball valve 200 to cut ofi the release of fluid from the chamber I90, but so as to permit the ball valve 200 to be held in the seated position by the spring 204 to prevent the supply of fluid under pressure to the chamber I90.

On each subsequent change in the pressure of the steam in the boiler of the furnace controlled by this control device, the device operates as described in detail above to effect movement of the piston I92 in the bore in the cylinder I94 in accordance with the extent of change in the pressure of the steam in the boiler of the furnace.

This control device includes means by which the extent of movement of the piston I92 in response to changes in the pressure of the steam in the boiler of the furnace controlled thereby may be adjustably varied is desired. This means comprises the screw 262, which is carried by the member 258, and which controls the position of the rod 260 relative to the rod 252.

If the screw 262 is adjusted so as to move the lower end of the rod 260 away from the rod 252, the amount of movement of the rod 260 necessary to produce a change in the force exerted by the spring 232 on the lever I14, and thereby on the diaphragm I50, equal to the change in the force exerted on this diaphragm as a result of a change in the pressure of the steam in the boiler will be reduced. This will be true because of the greater angle between the rod 260 and the rod 252 and the resultant greater movement of the lever 238 for a given movement of the rod 260.

Similarly, if the screw 262 is adjusted so as to permit the lower end of the rod 260 to move closer to the rod 252, the amount of movement of the rod 250 necessary to produce a change in the force exerted by the spring 232 on the lever I14, and thereby on the diaphragm I50, equal to the change in force exerted on this diaphragm as a result of a change in the pressure of the steam in the boiler will be increased. This will be true because of the smaller angle between the rod 260 and the rod 252, and the resultant smaller movement of the lever 238 for a given movement of the rod 260.

It will be seen that this control device is a compact unit free from projecting levers or balancing arms, and that it may be readily assembled and shipped as a complete unit.

It will be seen also that the smaller and less rugged portions of the device are surrounded and protected by the bracket I53 so that these portions will not be injured during shipment of the device.

In addition it will be seen that each of the control devices provided by this invention employs springs to oppose movement of the abutment of the control device subject to the steam in the boiler of the furnace to be controlled, and that means responsive to movement of the operating piston of the device is provided to vary the force exerted by these springs on this abutment so that the amount of movement of the operating piston is in accordance with the amount of change in the pressure of the steam in the boiler of the furnace controlled by the control device.

While two embodiments of the improved regulator for fuel burners provided by this invention have been illustrated and described in detail, it should be understood that the invention is not limited to these details of construction, and that numerous changes and modifications may be made without departing from the scope of the following claims.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a device for controlling the pressure of the fluid in a pressure system, in combination, a frame comprising a base portion adapted to be secured to a support and having spaced arms extending therefrom, a member supported adjacent the end of said arms and having a bore therein, a piston reciprocable in said bore in response to variations in the pressure of the fluid in the chamber at a face thereof and adapted to control the pressure of the fluid in said system, valve means for controlling the supply and release of fluid under pressure to and from said chamber, a stem disposed in a plane extending between said arms for actuating said valve means, a lever having one end pivotally supported on said arms adjacent the ends thereof, said stem being operatively connected with said lever at a point thereon spaced from the end thereof supported by said arms, a spring disposed between said arms and yieldingly urging said lever to move in one direction, means operated by said piston for varying the adjustment of said spring, and a pressure responsive device supported on said arms and adapted to be subjected to the pressure of the fluid in said system for moving said lever against said spring.

2. In a device for controlling the pressure of the fluid in a pressure system, in combination, a frame comprising a base portion adapted to be secured to a support and having spaced arms extending therefrom, a member supported adjacent the end of said arms and having a bore therein, a piston reciprocable in said bore in response to variations in the pressure of the fluid in the chamber at a face thereof and adapted to control the pressure of the fluid in said system, valve means positioned on the side of said member adjacent the frame base portion and in a plane extending between said arms for controlling the supply and release of fluid under pressure to and from said chamber, a stem disposed in a plane extending between said arms for actuating said valve means, a lever having one end pivotally supported on said arms adjacent the ends thereof, said stem being operatively connected with said lever at a point thereon spaced from the end thereof supported on said arms, a spring disposed between said arms and yieldingly urging said lever to move in one direction, means operative by said piston for varying the adjustment of said spring, and a pressure responsive device carried by said arms and adapted to be subjected to the pressure of the fluid in said system for moving said lever against said spring.

3. In a device for controlling the pressure of the fluid in a pressure system, in combination, a frame comprising a base portion adapted to be secured to a support and having spaced arms extending therefrom, a member supported adjacent the end of said arms and having a bore therein, a piston reciprocable in said bore in response to variations in the pressure of the fluid in the chamber at a face thereof and adapted to control the pressure of the fluid in said system, valve means for controlling the supply and release of fluid under pressure to and from said chamber, a stem disposed in a plane extending between said arms for actuating said valve means, a lever having one end pivotally supported on said arms adjacent the ends thereof, said stem being operatively connected with said lever at a point thereon spaced from the end thereof supported by said arms, a bell crank pivotally supported on said frame between said arms, a spring extending between said lever and an arm of said bell crank, an element having an inclined face thereon engaged by means carried by the other arm of said bell crank, said element being movable by said piston, and a pressure responsive device carried by said arms and adapted to be subjected to the pressure of the fluid in said system for moving said lever against said spring.

4. In a device for controlling the pressure of the fluid in a pressure system, in combination, a frame comprising a base portion adapted to be secured to a support and having spaced arms extending therefrom, a member supported adjacent the end of said arms and having a bore therein, a piston reciprocable in said bore in response to variations in the pressure of the fluid in the chamber at a face thereof and adapted to control the pressure of the fluid in said system, valve means for controlling the supply and release of fluid under pressure to and from said chamber, a stem disposed in a plane extending between said arms for actuating said valve means, a lever having one end pivotally supported on said arms adjacent the ends thereof, said stem being operatively connected with said lever at a point thereon spaced from the end thereof supported by said arms, a bell crank pivotally supported on said frame between said arms, a spring disposed between said arms and extending between said lever and one arm of said bell crank, the other arm of said bell crank carrying a roller, a guide roller supported on said frame, a wedge operative by said piston and extending between said rollers, and a pressure responsive device carried by said arms and adapted to be subjected to the pressure of the fluid in said system for moving said lever against said spring.

5. In a device for controlling the pressure of the fluid in a pressure system, in combination, a frame comprising a base portion adapted to be secured to a support and having spaced arms extending therefrom, a member supported adjacent the end of said arms and having a bore therein, a piston reciprocable in said bore in response to variations in the pressure of the fluid in the chamber at a face thereof and adapted to control the pressure of the fluid in said system, valve means for controlling the supply and release of fluid under pressure to and from said chamber, a stem disposed in a plane extending between said arms for actuating said valve means, a lever having one end pivotally supported on said arms adjacent the ends thereof, said stem being operatively connected with said lever at a point thereon spaced from the end thereof supported by said arms, a spring disposed between said arms and yieldingly urging said lever to move in one direction, means operated by said piston for varying the adjustment of said spring, and a pressure responsive device comprising a body supported on said arms, a diaphragm associated with said body and having at one side thereof a chamber adapted to be subjected to the pressure of the fluid in said system, a spring extending between said body and the other face of said diaphragm, and an element connecting the diaphragm and said lever.

JAMES W. HARRIE. 

